As a device which produces printed circuit boards on which multiple electronic components are mounted, there are a solder printer, a component mounting machine, a reflow furnace, a printed circuit board inspection machine, and the like, and there are many cases in which a printed circuit board production line is constructed by linking these. Of these, the component mounting machine is generally provided with a board conveyance device, a component supply device, and a component transfer device. The board conveyance device performs the carrying-in, carrying-out, and the positioning of the printed circuit board. The board conveyance device includes a conveyor device which performs the carrying-in and carrying-out of a printed circuit board in the mounting station by placing the printed circuit board and rotating the conveyor belts, and a clamp device which pushes up the printed circuit board to lift the printed circuit board from the conveyor device, positions the printed circuit board on the mounting station, and holds the printed circuit board. The component supply device supplies electronic components of a plurality of component types. Examples of the component supply device include a feeder supply device which supplies small chip components from a reel, and a tray supply device which supplies comparatively large electronic components from a tray. The component transfer device mounts electronic components on the printed circuit board. The component transfer device includes a mounting head which picks an electronic component from the component supply device and conveys the electronic component to the positioned printed circuit board, and a head driving mechanism which drives the mounting head.
PIE 1 discloses a technical example which enables the mounting of an electronic component on a long printed circuit board of a length exceeding the mounting station in this type of component mounting machine. In a printed circuit board assembly method of PTL 1, when a work head (the mounting head) on a printed circuit board (the long printed circuit board) which is positioned by a positioning device is no longer able to perform predetermined work, the position to which the printed circuit board is positioned is changed, and the work head performs the predetermined work. In other words, the position of the long printed circuit board is changed part way through a mounting operation, and the mounting is performed at each position from before and after the change.
As the component mounting machine, there is an automatic head exchanging type of device which selectively switches between a plurality of mounting heads and performs a mounting operation using the selected mounting head. In this case, for example, both a single nozzle head and a multi nozzle head are used as mounting heads. The single nozzle head is a head including one suction nozzle which picks an electronic component using a negative pressure. The multi nozzle head is a head including a revolver capable of holding and rotating, for example, four or twelve suction nozzles on a circular circumference.
In comparison to the single nozzle head, the multi nozzle head has the following characteristics. In other words, the multi nozzle head can pick a plurality of electronic components at once, and can mount the plurality of electronic components by merely performing a single reciprocal movement between the component supply device and the printed circuit board. Therefore, with the multi nozzle head, the average mounting time per single electronic component is short and the mounting efficiency is high. On the other hand, with the multi nozzle head, since the conveyance height when conveying the electronic components is reduced and the electronic components are in a low position when the revolver rotates, it is necessary to avoid interference between the electronic components on the bottom ends of the suction nozzles and the mounted electronic components. There are also restrictions in the separation distance between the plurality of suction nozzles in the multi nozzle head, and the types of component which can be mounted are limited to electronic components which are short and small.
In order to avoid the interference between the electronic components described above, first mounting the short and small electronic components which can be mounted using the multi nozzle head, and subsequently mounting the remaining electronic components using the single nozzle head is generally adopted as the mounting order. Accordingly, it is possible to make sufficient use of the high mounting efficiency of the multi nozzle head to shorten the total mounting time which is necessary for mounting all of the predetermined electronic components.
As the component mounting machine, there is a two head facing type of device in which a head driving mechanism which drives a mounting head is disposed on either side of the mounting station to interpose the mounting station. In this type of device, in most cases, the two mounting heads are of different types, and the component types of the electronic components to be mounted are divided therebetween. In order to avoid mutual interference between the mounting operations of the two mounting heads, generally, while one head driving mechanism enters the mounting station, the other head driving mechanism is not made to enter the mounting station.